Prevalence and prognostic importance of exercise limitation and physical inactivity in COPD

Exercise limitation and physical inactivity are separate, but related constructs. Both are commonly present in individuals with COPD, contribute to disease burden over and above the respiratory impairments, and are independently predictive of adverse outcomes. Because of this, clinicians should consider assessing these variables in their patients with COPD. Field tests of exercise performance such as the 6-min walk test and the incremental and endurance shuttle walk tests require limited additional resources, and results correlate with negative outcomes. Laboratory measures of exercise performance using a treadmill or cycle ergometer assess exercise capacity, provide prognostic information and have the advantage of explaining physiological mechanisms (and their interactions) underpinning exercise limitation. Limitations in exercise capacity (i.e. "cannot do") and physical inactivity (i.e. "do not do") are both associated with mortality; exercise limitation appears to be the more important driver of this outcome.

Monthly Follow-Ups of Functional Status in People with COPD: A Longitudinal Study

Functional status is an important and meaningful outcome in people with chronic obstructive pulmonary disease (COPD), although its measurement is not embedded in routine clinical assessments. This study described the functional status of people with COPD using the 1-min sit-to-stand test (1minSTS) over a 6-month period and the examined sociodemographic and clinical characteristics associated with this outcome. Data from a prospective study including people with COPD were analyzed. Functional status was assessed monthly with the 1minSTS over 6 months. Linear-mixed effect models assessed the 1minSTS number of repetitions mean change. One-hundred and eight participants (82.4% men; 66.9 ± 9.5 years) were included. A significantly lower number of repetitions in the 1minSTS over the 6-month period was associated with being female (estimate: −4.69, 95%CI: −8.20; −1.18), being older (estimate: −0.56, 95%CI: −0.77; −0.34), having higher BMI (estimate: −0.55, 95%CI: −0.81; −0.28) and having higher activity-related dyspnea (estimate: −2.04, 95%CI: −3.25; −0.83). Half of the participants showed improvements above three repetitions in the 1minSTS over the 6-month period, independently of their baseline impairment (1minSTS < 70% predicted: 52.5%; ≥70% predicted: 54.4%). To conclude, monthly follow-up assessments were associated with clinically relevant benefits in the functional status of people with COPD. Age, body composition, and activity-related dyspnea were the main predictors of functional status over time. Further research is needed to corroborate our findings and to support the beneficial effects of regular COPD monitoring.

Effect of expiratory loaded breathing during moderate exercise on intercostal muscle oxygenation

BACKGROUND

In patients with obstructive lung disease, maintaining adequate ventilation during exercise may require greater contraction of the respiratory muscles, which may lead to a compression of muscle capillaries. Furthermore, dynamic hyperinflation (DH) is frequent during exercise in these patients, as it allows to reach higher expiratory flows and to satisfy respiratory demand. However, in such situation, intercostal muscles are likely to be stretched, which could affect the diameter of their capillaries. Thus, in a context of high level of expiratory resistance, intercostal muscle oxygenation may be disturbed during exercise, especially if DH occurs.

METHODS

Twelve participants (22±2 years) performed two sessions of moderate exercise (20 min) by breathing freely with and without a 20-cmH2O expiratory threshold load (ETL). Tissue saturation index (TSI) and concentration changes from rest (Δ) in oxygenated ([O2Hb]) and total haemoglobin ([tHb]) were measured in the seventh intercostal space using near-infrared spectroscopy. Respiratory, metabolic and cardiac variables were likewise recorded.

RESULTS

Throughout exercise, dyspnea was higher and TSI was lower in ETL condition than in control (p<0.01). After a few minutes of exercise, Δ [O2Hb] was also lower in ETL condition, as well as Δ [tHb], when inspiratory capacity started to be reduced (p<0.05). Changes in [O2Hb] and dyspnea were correlated with changes in expiratory flow rate (Vt/Te) (r = -0.66 and 0.66, respectively; p<0.05).

CONCLUSION

During exercise with ETL, impaired muscle oxygenation could be due to a limited increase in blood volume resulting from strong muscle contraction and/or occurrence of DH.

The impact of pulmonary rehabilitation on severe physical inactivity in patients with chronic obstructive pulmonary disease: a pilot study

Introduction

In patients with COPD, severe physical inactivity (SPI, which is defined as total daily energy expenditure/resting energy expenditure; physical activity level [PAL] ratio, <1.4) is associated with increased morbidity and mortality. Pulmonary rehabilitation (PR) increases physical capacity in COPD, but the impact on SPI is unknown. In this study, we aimed at elucidating the prevalence of SPI in COPD patients attending standard PR, the impact of PR on SPI prevalence, and the relationship between SPI and time spent in moderate physical activity thus whether American College of Sports Medicine (ACSM) recommendations are clinically useful in excluding SPI in COPD.

Methods

This is a prospective non-interventional pilot study on patients with COPD completing PR, consenting to wear an accelerometer (Sensewear^© Armband) for a week before and after completing PR to assess changes in energy expenditure, time spent in physical activity, and number of daily steps. Low level of daily physical activity was not an inclusion criterion.

Results

In total, 57 patients completed the study and 31 (54%) had SPI at baseline. In patients with SPI, baseline median FEV₁ was 48 (range, 28–86) % of predicted and GOLD B, n=11 (35%)/GOLD D, n=20 (65%). Surprisingly, 31 of SPI patients (97%) spent ≥150 minutes/week in moderate physical activity. After rehabilitation, 24 (78%) did not change activity level and were persistently SPI. We observed no differences at baseline between patient responding (n=7) vs not responding (n=24) to PR. Responders increased number of daily steps and time spent in lighter but not moderate physical activity during rehabilitation.

Conclusion

In this pilot study, SPI was prevalent, and PR had limited impact. Contraintui-tively, most patients with SPI complied with general recommendations of weekly hours spent in moderate physical activity. Our study highlights that increasing time spent in light activity rather than improving time spent in moderate activity is important in COPD patients with chronic dyspnea.

Perceptions of Patients With Chronic Obstructive Pulmonary Disease and Their Physiotherapists Regarding the Use of an eHealth Intervention

Background

If eHealth interventions are not used (properly), their potential benefits cannot be fulfilled. User perceptions of eHealth are an important determinant of its successful implementation. This study examined how patients with chronic obstructive pulmonary disease (COPD) and their physiotherapists (PHTs) value an eHealth self-management intervention following a period of use.

Objective

The study aimed to evaluate the perceptions of COPD patients and their PHTs as eHealth users.

Methods

In this study, an eHealth self-management intervention (website and mobile phone app) aimed at stimulating physical activity (PA) in COPD patients was evaluated by its users (patients and PHTs). As participants in a randomized controlled trial (RCT), they were asked how they valued the eHealth intervention after 6 months’ use. Interview requests were made to 33 PHTs from 26 participating practices, and a questionnaire was sent to 76 patients. The questionnaire was analyzed in Excel (Microsoft). The interviews with the PHTs and text messages (short message service, SMS) sent between patients and PHTs were transcribed and independently coded in MAXQDA 10 for Windows (VERBI GmbH).

Results

A total of 60 patients with COPD filled out the questionnaire, and 24 PHTs were interviewed. The mobile phone app was used 89.0% (160.2/180 days) (standard deviation [SD] 18.5) of the time by patients; 53% (13/24) of PHTs reported low or no use. Patients scored the ease of use of the app 5.09 (SD 1.14) (on a 7-point scale). They found the presentation of the PA information in the app to be clear, insightful, and stimulating. All PHTs judged the website as explicit and user-friendly but had trouble devising a new PA goal for their patients. Patients mostly sent informative, neutral messages concerning the PA goal, and PHTs sent mostly motivating, positive messages concerning the PA goal. Messages were not perceived as supportive in reaching the PA goal according to the patients. Perceived usefulness of the intervention for the PHTs was the objective measurement of PA, the ability to see PA patterns over time, and the ability to use the intervention as a tool to give their patients insight into their PA. For patients, it was that the intervention supported them in increasing their PA and that it made them feel fitter. Barriers to use of the intervention according to the PHTs were time constraints and financial reasons. Seventy-nine percent (19/24) of the PHTs and 58% (35/60) of the patients mentioned they would be interested in using the intervention in the future.

Conclusions

PHTs and COPD patients had positive feelings regarding the functionality and potential of the eHealth self-management intervention. This paper addresses a number of topics that may aid in the successful development and implementation of these types of eHealth interventions in the future.

Psychometric properties of the Physical Activity Scale for the Elderly in Chinese patients with COPD

BACKGROUND

For patients with COPD, physical activity (PA) is recommended as the core component of pulmonary rehabilitation, but there is lack of a validated questionnaire for assessing the PA effectively.

AIM

To evaluate the reliability and validity of the Chinese version of Physical Activity Scale for the Elderly (PASE-C) in patients with COPD.

METHODS

A cross-sectional study was conducted with 167 outpatients aged 60 years or older with COPD. Test-retest reliability and internal consistency were calculated by intraclass correlation coefficient (ICC) and Cronbach's coefficient α, respectively. Validity was evaluated by correlation with the International Physical Activity Questionnaire-Short (IPAQ-S), data of pedometer, Self-Efficacy for Managing Chronic Disease 6-Item Scale (SES6), Hospital Anxiety and Depression Scale (HADS), Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), grip strength, and disease characteristics.

RESULTS

The PASE-C had an excellent seven-day test-retest reliability (ICC=0.98) and an acceptable internal consistency (Cronbach's α=0.71). The content validity was supported by an item-content validity index, a scale-content validity index/universal agreement, and a scale-content validity index/average value of 0.70-1, 0.70, and 0.93, respectively. Concurrent validity was tested by correlation with IPAQ-S (r=0.651). Criterion validity was confirmed by correlation with the walking steps (r=0.611) and energy expenditure (r=0.493). For construct validity, PASE-C had correlations with SES6 (r=0.396), HADS for depression (r=-0.234), seven subscales of SF-36 (r=0.182-0.525), grip strength (r=0.341), and disease characteristics including the duration of COPD (r=-0.215), modified British Medical Research Council scale (r=-0.354), forced expiratory volume in one second as percentage of predicted (r=0.307), and Global Initiative for Chronic Obstructive Lung Disease grade (r=-0.264), with a good construct validity (all P<0.05).

CONCLUSION

The PASE-C has acceptable reliability and validity for patients aged 60 years or older with COPD, and it can be used as a valid tool to measure the PA of patients with COPD in the People's Republic of China.

Profile of patients with chronic obstructive pulmonary disease classified as physically active and inactive according to different thresholds of physical activity in daily life

Objective

To compare the profiles of patients with chronic obstructive pulmonary disease (COPD) considered physically active or inactive according to different classifications of the level of physical activity in daily life (PADL).

Method

Pulmonary function, dyspnea, functional status, body composition, exercise capacity, respiratory and peripheral muscle strength, and presence of comorbidities were assessed in 104 patients with COPD. The level of PADL was quantified with a SenseWear Armband activity monitor. Three classifications were used to classify the patients as physically active or inactive: 30 minutes of activity/day with intensity >3.2 METs, if age ≥65 years, and >4 METs, if age <65 years; 30 minutes of activity/day with intensity >3.0 METs, regardless of patient age; and 80 minutes of activity/day with intensity >3.0 METs, regardless of patient age.

Results

In all classifications, when compared with the inactive group, the physically active group had better values of anthropometric variables (higher fat-free mass, lower body weight, body mass index and fat percentage), exercise capacity (6-minute walking distance), lung function (forced vital capacity) and functional status (personal care domain of the London Chest Activity of Daily Living). Furthermore, patients classified as physically active in two classifications also had better peripheral and expiratory muscle strength, airflow obstruction, functional status, and quality of life, as well as lower prevalence of heart disease and mortality risk.

Conclusion

In all classification methods, physically active patients with COPD have better exercise capacity, lung function, body composition, and functional status compared to physically inactive patients.

Nordic walking enhances oxygen uptake without increasing the rate of perceived exertion in patients with chronic obstructive pulmonary disease

BACKGROUND

In healthy subjects, Nordic walking (NW) generates higher oxygen uptake (V˙O2) than standard walking at an equal rate of perceived exertion (RPE). The feasibility and positive outcomes of NW in patients with chronic obstructive pulmonary disease (COPD) have been reported.

OBJECTIVES

The aim of the current study is to assess the physiological responses and RPE during NW in COPD patients.

METHODS

In 15 COPD patients [mean (SD) age 67 (9) years] with a forced expiratory volume in the 1st s of 55% (15)], V˙O2, minute ventilation and heart rate were measured with a portable system during the 6-min walking test (6MWT), incremental shuttle walking test (SWT), 6-min NW on solid ground (6mNWground) and 6-min NW on soft dry beach sand (6mNWsand). The RPE using a modified Borg scale was assessed after each test.

RESULTS

6mNWground and 6mNWsand showed a higher V˙O2 plateau compared with the 6MWT and peak V˙O2 measured during SWT [mean (SD) V˙O2 21 (3), 22 (4), 18 (4) and 19 (5) ml·kg(-1)·min(-1), respectively; p < 0.05 each]. However, no differences in RPE were observed among 6mNWground, 6MWT and SWT [modified Borg scale score for dyspnea 4.2 (2.0), 4.1 (1.8) and 4.3 (1.7), respectively; nonsignificant]. However, RPE in 6mNWsand was significantly higher than in all the other exercise protocols [modified Borg scale score for dyspnea 5.2 (2.2); p < 0.05].

CONCLUSIONS

In COPD patients, the use of Nordic poles generates higher V˙O2 than standard walking with no differences in the dyspnea score. The results indicate the potential to enhance community-based training programs in these patients. © 2015 S. Karger AG, Basel.